MAX14578E Maxim, MAX14578E Datasheet - Page 14

• Manufacturer Part Number: MAX14578E
• Description: The MAX14578E/MAX14578AE are USB charger detectors compliant with USB Battery Charging Revision 1
• Manufacturer: Maxim

The MAX14578E/MAX14578AE are USB charger detec-
tors compliant with USB Battery Charging Revision 1.1.
The USB charger-detection circuitry detects USB stan-
dard downstream ports (SDPs), USB charging down-
stream ports (CDPs), or dedicated charger ports (DCPs),
and controls an external lithium-ion (Li+) battery charger.
The MAX14578E features I
MAX14578AE features an EN pin and an LDO output pin.
The internal USB switch is compliant to Hi-Speed USB,
full-speed USB, and low-speed USB signals. Both devic-
es feature low on-resistance, low on-resistance flatness,
and very low capacitance.
The typical Micro/Mini-USB connector has five signal
lines: USB power, two USB signal lines (D-, D+), ID line,
and ground. The USB power on the Micro/Mini-USB con-
nector connects to V
The two USB signal lines, D- and D+, connect to CD- and
CD+.
The
(480Mbps), full-speed (12Mbps), and low-speed USB
(1.5Mbps) signal levels. The USB channel is bidirectional
and has low 3.3I (typ) on-resistance and 4.5pF (typ)
on-capacitance. The low on-resistance is stable as the
analog input signals are swept from ground to V
for low signal distortion.
The LOUT LDO provides a 5.3V (typ) output, used to
power a USB transceiver. Most USB transceivers are
powered from a 3.3V or higher voltage that is difficult to
derive from a Li+ battery. One solution is to power the
transceivers from the USB V
can rise as high as +28V in a fault condition. The LOUT
pin provides a voltage-limited supply that protects the
USB transceiver from these high voltages. When V
rises above 9.0V (typ), the MAX14578AE detects an
overvoltage fault and LOUT goes to 0V. Additionally,
USB Battery Charger Detectors
14
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MAX14578E/MAX14578AE
LOUT LDO Output (MAX14578AE Only)
B
Input Sources and Routing
on the MAX14578E/MAX14578AE.
Detailed Description
2
C communication, while the
BUS
power; however, V
support
USB (CD-, CD+)
Hi-Speed
SWPOS
BUS
BUS
LOUT features a 100mA (typ) current limit to protect the
device in the event of a short circuit.
The MAX14578E generates an interrupt for any change in
VBCOMP, and when DBCHG or DCD_T transitions from
0 to 1. The INTEN bit in the CONTROL 1 register (0x01)
enables interrupt output. When INTEN is set to zero, all
interrupts are masked but not cleared. A read to the
INTERRUPT register (0x02) is required to clear interrupts.
To avoid multiple interrupts at the insertion of an acces-
sory and for added noise/disturbance protection, a
30ms (typ) debounce timer is present that requires an
inserted or removed state hold for the debounce time
before it sends an interrupt.
The MAX14578E has two I
register (0x01) dedicated to low-power operation:
LOW_POW and CP_ENA.
LOW_POW sets low-power mode. In low-power mode,
the internal oscillator is turned off under the following
conditions: no V
When enabled, all switches are high impedance (note
that no negative rail voltage can be applied).
CP_ENA controls the charge pump required for proper
operation of the analog switches. When set to disable,
no negative rail voltage can be applied. A factory default
sets CP_ENA = 0 automatically.
The MAX14578E includes internal logic to detect if a valid
USB charger is connected. When a valid V
applied to V
register is set to 1, the MAX14578E/MAX14578AE begin
the charger-type-detection sequence (see Figure 1).
During the charger-type-detection sequence, the CD-
and CD+ switches are open, and once the sequence
completes, the switches return to their previous state.
Figure 2 shows a timing diagram for an example char-
ger-type-detection sequence.
B
or when CHG_TYP_M in the CONTROL 1
BUS
, USBSWC = 0, and CP_ENA = 0.
USB Charger Detection
2
C bits in the CONTROL 1
Low-Power Modes
Detection Debounce
BUS
Interrupts
voltage is